The researchers performed electrophysiological experiments to show that the effects they observed were indeed due to the inward flow of ions caused by activation of the ChR2 protein by light; this inward ion flow persisted for the duration of blue-light exposure.
Future work may include studies using forms of ChR2 or related proteins that are sensitive to different wavelengths of light; by allowing remote-control activation of different neurons and muscle cells within an individual animal, such approaches could aid in understanding the circuitry and control of complex behaviors.